I think an enclosure is the ultimate fix, but you can also try increasing the extrusion temp and flow rate.
For ABS, I like 240 - 245C, increase the flow to 1 or 1.1. Turn off fan or set the fan to max of 40- 50%. Higher temps, more filament extruded and no cooling should all help binding to the previous layer. Best to experiment with each parameter then combination… Higher temp and no cooling works best for me. With S3D it allows for better control of extrusion temps and cooling…
The things to watch out for:
- Temps too high causes ooze or spider webs when nozzle is just moving
- Flow rate too high when nozzle scapes or runs into print.
- Fan too high if parts delaminate / curl while contracting.
HTH… at least until you decide if you want to build n enclosure.